someone is offering me 4.5k or Crimson ghost for my radio force
which one should i accept?

ghosts aren't really seen ingame... its just that shadow that comes out you know...
you wont use ur ghost in a toribash video.. and of course if you post a replay to someone... he/she wont stop the replay to check the color of ur ghost...
so if i was u i would pick the TC...

Tc is more useful, you can save it up until you see an item you want to buy. Nobody wants to buy that ghost.